The invention discloses a network card fixing module, a case and a network card installation method, and is applied to the field of network card installation, the network card fixing module comprises a board card support used for installing a board card, and the board card is provided with a network card connector for inserting a network card; the first supporting component is installed on the board card support, and a first bearing part is arranged on the first supporting component and used for being detachably connected with the first end of the network card; the second supporting part is installed on the board card support and located on the side, away from the first supporting part, of the network card connector; one end of the main body bracket is connected with the first supporting component, and the other end is connected with the second supporting component. According to the network card fixing module provided by the invention, the network card can be limited and supported by virtue of the limiting space defined by the first supporting part, the second supporting part, the board card bracket and the main body bracket, so that the position stability of the network card is ensured, and the shaking is reduced, thereby ensuring the smooth operation of the network card and improving the installation reliability of the network card.