To describe the motion state of multijointlinkage in series transformation, a method to solve the motion state and attitude position by measuring the magnetic induction density and acceleration is studied. The angle calculation is performed by employing the direction cosine transformation between the geographical coordinate and the basic coordinates of the magnetic and gravitational fields of the earth. The mode of the attitude angle, denoted by the magnetic induction density and acceleration, is obtained. The angle transformation during the coordination transformation is analyzed. The relationship between attitude angle of the linkage and the angle of the linkage in the series transformation is deduced. An example is used to verify the model. This model can solve the transformation problem between attitude angle and real angle, which is the same as the motion expression of the body.