A tea brewing device capable of automatically controlling the water quantity and the water temperature comprises a shell and a control circuit arranged inside the shell. The tea brewing device is characterized in that the control circuit comprises a single chip microcomputer used for data processing, the single chip microcomputer is connected with an alarm, a heater, a pressure sensor and a temperature sensor, the pressure sensor is used for monitoring the water quantity, and the temperature sensor is used for monitoring the water temperature; a control panel used for setting the water quantity and the water temperature is arranged on the top of the shell, the control panel is connected with the input end of the single chip microcomputer, a display screen used for displaying parameter values is arranged at the upper portion of the front face of the shell, the display screen is connected with the output end of the single chip microcomputer, a cup base used for containing a water cup is arranged below the display screen, a water outlet is formed above the cup base, the water outlet is connected with the single chip microcomputer through an electric control water valve, a water inlet is formed in the top of the shell, the water inlet is connected with a water storage box inside the shell, a collecting contact of the temperature sensor is arranged on the wall of the water storage box, and the heater is arranged at the bottom of the water storage box. The tea brewing device is easy to operate and saves time.