The reverse order laws for {1,2,3}-inverse and {1,2,4}-inverse of product of two matrices have been studied by applying the product singular value decomposition P-SVD and the characters of generalized inverse. The necessary and sufficient conditions of (AB){1,2,3}⊆B{1,2,3}A{1,2,3} and (AB){1,2,4}⊆B{1,2,4}A{1,2,4}are obtained. Then equivalent conditions of (AB){1,2,3}=B{1,2,3}A{1,2,3} and (AB){1,2,4}=B{1,2,4}A{1,2,4} are obtained.