The invention discloses a positioning method for a digital electric valve. A positioner consists of a control unit, an I/P electric conversion unit, a valve position feedback unit and a fault diagnosis unit. The positioning method includes the following steps: flow characteristic parameters of the positioner are configured; on the basis of providing the entire diversified flow characteristics andacting directions of an adjusting valve, correction is carried out aiming at work flow characteristic distortion caused by factors such as the change of the pressure drop ratio of the adjusting valveand the like; the valve position control of the adjusting valve is based on a Fuzzy-PI dual-mode non-interference switching algorithm; the fault diagnosis depends on internal relationships among a valve position given value, a valve position feedback value and valve film head pressure which are set by a control center, and a user selects to release or partially release the valve film head pressure when in valve stuck freeing operation according to the rule-based knowledge reasoning, so as to realize the fault diagnosis; the valve displacement/electric conversion of the valve position feedbackunit depends on a non-contact magnetic sensitive potentiometer, the man-machine interaction adopts the touch screen technology, and the control unit accesses to a control network by an Ethernet interface.