The invention discloses a water tank with a faucet capable of being installed conveniently. The water tank comprises a water tank platform, the faucet and a connecting device, an extension section extending downwards is arranged at the lower end of the external tube wall of the faucet, the hole side wall of the extension section is provided with a threaded hole, a tightly abutting screw is connected to the threaded hole, the water tank platform is provided with an elliptic installation hole, the bottom face of the water tank platform is provided with a fixing shaft extending downwards, and the fixing shaft is near the installation hole; the connecting device is composed of a tubular connector provided with a through hole and an end cover, the upper end of the tubular connector is provided with an external thread, an elliptic convex wall is arranged on the periphery of the lower end of the tubular connector, and the elliptic convex wall is matched with the installation hole in the water tank platform; the top wall of the end cover is provided with through holes, a lower opening hole of the end cover is provided with an internal thread, the internal thread is matched with the external thread of the tubular connector, and the size of the end cover is matched with the lower opening hole of the faucet.