Taking the typical crankshaft hole clamp of diesel engine fuselage as an example, the influences of V-block angle error on the fuselage deformation under the crankshaft hole clamp state were analyzed by using finite element analysis method. By changing the angle of V-block and the contact state between the body and V-block, the possible contact condition and stress state of the diesel engine body were analyzed; all contact conditions of the body were simulated by using ABAQUS simulation software to obtain the deformation amount of one busbar of the crankshaft hole system and the cross-section joint of the body, and it was used as the evaluation index of the deformation under the clamping condition of crankshaft hole of the body; according to the angle error and the state of contact area, the components of clamping error were discussed and the influence rules of clamping error were analyzed. The results show that within a certain angular error range, the larger the angle is, the larger the deformation of the fuselage is; when the angles of V-shaped blocks are the same, the cross line surface contact has little effect on the fuselage deformation; under the condition that the crankshaft hole of the diesel engine body is clamped, the A3-E2 contact state has the least effect on the deformation of the engine body; the fuselage is bent deformed in the x and y directions,and twisted deformed in the z direction.