Abstract: To obtain the elastic element’s dynamic load under the action of slope pulse load in the lifting process， we simplified the crawler crane boom system as a linear vibration model with two degrees of freedom. Through the motion analysis， the geometry equations of deformation caused by elastic element’s vibration was established. The vibration mathematical model of the slope pulse load was established through energy’s method， and we also used superposition principle method to calculate elastic element’s the response，including displacement，velocity，acceleration and dynamic load coefficients of the linear vibration system with the greatest loading， under the slope pulse load. The effective control method can not only connect with the major factors about the dynamic load， but also provide practical basis for the equipment’s working performance.

Key words: cranes, kinetics, dynamic coefficient, vibration