介绍了一种由步进电机作为电机械转换元件的数字阀的实现电液（ 气） 直接数字控制的新方法。该方法通过控制步进电机相邻相序通电时间的长短实现阀的输出信号的连续可控。应用这种方法解决了传统的步进式电液（ 气） 控制元件的所存在的响应速度与精度之间的矛盾；同时保持其固有的重复精度高、无滞环及线性度好的优点。文中给出利用阀芯的双自由度原理设计的数字伺服阀在连续跟踪控制下的实验结果，表明采用新的数字控制的方法可使阀获得理想的动静特性 A new method of direct digital control of electro-hydraulic (gas) by digital motor with stepper motor as electrical-mechanical conversion element is introduced. The method achieves continuous and controllable output signal of the valve by controlling the length of the energization time of the adjacent phase sequence of the stepping motor. The application of this method solves the conflict between the existing response speed and precision of the conventional stepping electro-hydraulic (gas) control element while maintaining the inherent advantages of high repetition accuracy, no hysteresis and good linearity. The experimental results of the digital servo valve designed by using the principle of two degrees of freedom of the valve core under the continuous tracking control are given in the paper. The results show that the new digital control method can make the valve obtain the ideal dynamic and static characteristics