Aimed at the small flow rate in transportation of Y type channel valveless piezoelectric pump, a kind of Y type double entry double outlet water valveless piezoelectric pump structure was designed. The pumped medium flowed smoothly without the formation of turbulent flow, so it could be used for conveying blood cells and molecular biology group. Theoretical analysis was carried on the piezoelectric vibrator. Through comparing experiment with Y type single in single out flow tract of the piezoelectric pump, the conclusion that by increasing the number of channels could improve the conveying flow of valve less piezoelectric pump was proved.