It was hard to calculate the flow pulsation of cycloidal gear pump with muti-teeth difference, because of numerous and complex influence factors, so the great difficulty was taken to practical engineering application. Through the study of meshing theory of the cycloidal gear with multi-tooth number difference, an accurate method to solve flow pulsation of uneven factors was put forward, at the same time, the significant degree of influence of various parameters to the flow pulsation was analyzed through Orthogonal experimental method. Those studies provide a theoretical basis for choosing of parameters in the design process of low flow pulsation cycloidal gear pump with muti-tooth number difference.