The crankshaft is very important in high-power drilling pump. The information on the vibration mode and frequency response is critical for the crankshaft to work normally in drilling pump. ANSYS finite element analysis software was used to implement the modal analysis of the crankshaft thus obtaining characteristic frequency and the corresponding vibration mode and then by the harmonic response analysis which was carried out based on the modal analysis, dynamic response of the crankshaft was obtained. The result shows that the working speed of crankshaft can avoid the region of sympathetic vibration effectively, no resonance will happen. The strength and fatigue life of crankshaft are also checked according to the stress results. The analysis also makes a base for the optimized design of dynamic performance of the crankshaft.