The invention relates to a multi-mode modulation and display device of a computer power supply heat dissipation fan .the input end is connected with a required power supply, and the output end is electrically connected with the heat dissipation fan.the multi-mode modulation and display device comprises a trigger element, a control unit, a switching and display module and a sensing and distributing unit, wherein the trigger element is controlled by a user to generate a sudden wave signal to actuate the control unit to generate sequence for actuation; The input end of the control unit is connected with the trigger element; The switching and display module consists of at least three switching and display units, the input ends of which are respectively connected with the output ends of the control units; The sensing distribution unit is correspondingly connected to the output end of the switching and display module and comprises a sensor and at least two resistors with high and low different resistance values, wherein the sensor is actuated by the drive control of one of the switching and display units; One end of the high and low resistors with different resistance values is respectively connected with another switching and display unit, and the other end of the resistor is provided with a heat dissipation fan.