An LED display module and an LED displayer are disclosed. The LED display module comprises a module bottom shell and a circuit board installed in the module bottom shell. The module bottom shell comprises a shell body and a first heat-dissipation cover disposed over a first open region of the shell body. The LED display module further comprises a power supply and a receiving card which are electrically connected to the circuit board. The power supply is located between the first heat-dissipation cover and the circuit board. The receiving card is located between the shell body and the circuit board. The LED display module is ultra-thin, and the LED displayer is made ultra-thin, accordingly.