In some specific micro-traffic scenarios, the driving space and satisfaction of the vehicle will be affected if the lane is not changed, and the safety and comfort of the vehicle will be affected if the lane is changed. Local path planning emphasizes that a driving path is exported in the micro-traffic scenario, and high safety and comfort are required for the path points at each discrete time. At present, the local path planning method rarely considers the physical characteristics such as whether the path curvature is continuous or not, and the constraint of path origin and destination, and studies the lane change decision and planning method based on the safe lane change domain. Two typical lane-changing scenarios are analyzed, and the maximum and minimum safe lane-changing angle models are established respectively. For the double-barrier vehicle lane-changing scenario that cannot evolve into a single obstacle vehicle lane-changing scenario, the safe lane-changing domain is established. In the same scene, the polynomial curve, Dubins curve, sine curve and B-spline curve are compared. Based on the curvature of the starting and ending points of the lane changing and the curvature change in the lane changing process, the B-spline curve method is selected as the local path planning method, which verifies the feasibility of using B-spline curve to carry out the local path planning, and determines the optimal lane changing path based on the safe lane changing domain by using the lane changing time and the average curvature of the lane changing path. By traversing all possible lane change scenarios, the conversion of typical lane change scenarios is realized through lane change pre-operation, and the rule lane change decision based on safe lane change domain is proposed for collision detection. Combined with Simulink and PreScan computing platform, the simulation verification of the proposed lane changing strategy is realized in typical lane changing scenarios. It can be seen from the curves of three vehicles' transverse and longitudinal positions with time that there is no collision between the vehicle and the obstacle vehicle in two lanes. The complete lane change process is divided into six stages: constant speed cruise, constant deceleration, constant speed following, acceleration before lane change, lane change and constant speed cruise overtaking lane. The variation curves of velocity and longitudinal position with simulation time further verify the safety of lane change decision and planning strategy. The results show that when the vehicles are changing lanes, the safe lane changing area needs to be established in the case of the same speed of the two obstacles. The analysis shows that the B-spline curve can realize continuous curvature change, and the curvature of the starting and ending points is zero. Therefore, the B-spline curve can be used to plan the lane changing path, and the comprehensive evaluation function surface can be established to select the optimal lane changing path curve. The lane-changing scene can be simplified as a single obstacle lane-changing scene through the driver's lane-changing pre-operation, and the appropriate lane-changing angle can be determined in the range of the maximum or minimum critical safe lane-changing angle to ensure the safe lane-changing of the vehicle. The model established in this paper has good practicability, which provides a reference for the research of automatic lane change auxiliary system and automatic overtaking auxiliary system of intelligent vehicles, and can serve the design and evaluation of intelligent traffic safety in the future.