A connection module is disposed in a main circuit board and includes a card edge connector, a hard circuit board and two connectors. The card edge connector is fixedly disposed on the main circuit board. The hard circuit board has a board body and a connecting tongue for correspondingly plugging with the card edge connector. The board body is configured with a disconnecting notch, and the board body is separated by the disconnecting notch into two floating plates arranged side by side at an interval and floatable using the disconnecting notch. The connectors are respectively fixed to the floating plates. Thus, without needing an additional guide frame, the connectors are enabled to float in any desired direction, thereby achieving effects of reducing an overall height and satisfying current thinning requirements.