The invention belongs to the technical field of fans and in particular relates to computer fan equipment with a back-flow preventing function. The computer fan equipment with the back-flow preventingfunction comprises a base, a bracket, a driving motor and a fan body, wherein the bracket is fixed on the base; the driving motor is mounted on the bracket; the fan body is mounted on an output shaftof the driving motor; due to a control device additionally arranged on the fan, the reliability of the fan is reduced, and the practicability is reduced; in particular during long-time use, a first spring in the fan can be damaged to fail to work, and fan blades cannot realize normal side swinging or returning; according to the computer fan equipment with the back-flow preventing function, in thisstate, the fan blades incapable of realizing normal side swinging swing to be opened under the driving of wind power; during returning, an adjusting ring is pressed down through a return spring, andthe adjusting ring drives the fan blades, which do not return, to swing to return; opening and returning functions of the corresponding fan blades are realized after the first spring is damaged; and in addition, through a disengaging structure of a slide block and a slide sleeve, it is guaranteed that the fan cannot be limited by thread fit between the slide block and a fixing shaft during swinging under the effect of wind in the case that the first spring is damaged.