Three factors，i.e. dynamic stress amplitude，vibration frequency and confining pressure，are considered for the orthogonal test design of 3 factors and 3 levels. And according to the orthogonal design，dynamic triaxial tests are carried out to study the axial accumulated strain，dynamic pore water pressure and dynamic elastic modulus of lacustrine soft soil under cyclic loads. Then the sensitivity analysis method is employed to research the sensitivity of each dynamic characteristic index influenced by various loading factors. Results show that the dynamic stress amplitude is the most significant impact factor to the axial accumulated strain，dynamic pore water pressure and dynamic elastic modulus. Confining pressure is the secondary factor affecting the axial accumulated strain and dynamic elastic modulus，and vibration frequency is the secondary factor influencing the dynamic pore water pressure.