An instantaneous blood pressure measurement device based on volume compensation was developed, and a measurement control method was tested and improved on the device. The device consists of a cylindrical finger cuff, a compact proportional solenoid valve, an air pump and a hardware circuit. Finger cuff contains a pair of led and photo-diode. The hardware circuit consists of a feedback controls circuit and a signal processing circuit based on a microprocessor controller. A neural network predictive controller is proposed to replace the traditional PID controller for experiments. Simulation and experiments show that the neural network predictive controller has better control effect than the traditional PID controller.