Coffee machine

The utility model discloses a coffee machine. Beverage box and water tank, the beverage box is communicated with the water tank through a waterway pipeline; the waterway pipeline extends into the bottom of the water tank; the device is characterized in that a pressure relief hole, a pressure relief valve and a water filling port with a sealing device are arranged at the top of the water tank; thebottom of the water tank extends downwards to form a U-shaped heating pipe; a water feeding pipe is longitudinally arranged in the water tank; the water inlet end of the U-shaped heating pipe is communicated with the water tank, the water outlet end of the U-shaped heating pipe is communicated with the water feeding pipe, the water inlet end of the U-shaped heating pipe is provided with a one-wayvalve for controlling water flow to enter the U-shaped heating pipe from the water tank, the diameter of the pressure relief hole is smaller than 1 mm, and the pressure relief pressure of the pressurerelief valve is smaller th