Abstract: In the light of the multifunctional eletrohydraulic valve's (MVE) working principle and its performance curve, a constant flow regulating model has been built in auto-loading system. The constant flow regulation for the electrohydraulic valve has been realized by adopting the PD algorithm. The constant flow regulation software package is developed with C language for the MEV, the program of which includes master program or executive program, interrupt service routine, sampling and MEV regulation program. It shows by practice that the software package can obtain a better result of the constant flow.