In order to studythe effect of excitation direction on the output performance of vibration energy harvester(VEH), the dynamic model and the output model of piezoelectric effect are obtainedfor a single cantilever beam energy harvester under vibration excitation in any direction. The direction of vibration is defined by two angle parameter φ and θ from spherical coordinate system.According to the theoretical analysis and simulation, it is found that the absorption efficiency of the energy harvester varies ascosine function with the increase of φ when the vibration excitation direction varies, and varies assine function with the increase of θ.But the influence of φ on the collection efficiency is much greater than the influence of θ. Experimental results show that when θ=0° and φ increases from 0° to 90°, the efficiency of the VEH decreases from 9353% to 288%. When φ=90° and θ increase from 0° to 90°, the efficiency increases from 288% to 388%. The relationship of VEH′s output with the vibration direction is obtained, which can providecertain reference value for the research of VEH with cantilever beam.