Display module, manufacturing method thereof and display device

The embodiment of the invention discloses a display module, a manufacturing method thereof and a display device. In one specific implementation mode, the display module comprises a display panel, a heat dissipation film, an ultrasonic fingerprint module and a light shielding layer, the heat dissipation film comprises an opening, the ultrasonic fingerprint module comprises a sensor and a flexible circuit board bound with the sensor, the sensor is attached to the side, away from a display, of the display panel in the opening, the heat dissipation film further comprises a plurality of open grooves, and the plurality of open grooves are formed in the light shielding layer. The plurality of slots are connected with the opening and are at least arranged on the first side edge of the heat dissipation film, one side edge of each slot coincides with the side edge of the opening and is at least arranged on the first edge of the heat dissipation film, and the length of the side edge, coinciding with the opening, in each slot is smaller than or equal to 1/10 of the length of the side edge of the opening. According to the display module in the embodiment, the multiple open grooves connected with the opening are formed in the heat dissipation film, so that the area, exposing the display panel, in the opening can be fully filled with the shading layer by means of capillary force of the open grooves, and light leakage is avoided.