A gas pressure regulator includes a valve body and a valve cover. The valve cover is covered on the valve body. The valve body is provided with a valve cavity, and the valve cavity is connected to an air inlet channel and an air outlet channel. The valve cavity includes a primary pressure regulating cavity and a secondary pressure regulating cavity, and the primary pressure regulating cavity and the secondary pressure regulating cavity are communicated with each other through a valve port. The primary pressure regulating cavity is communicated with the air inlet channel, and a valve core pressure regulating assembly is disposed between the primary pressure regulating cavity and the air inlet channel. The secondary pressure regulating cavity is communicated with the air outlet channel. A lever pressure regulating assembly is disposed between the valve port and the secondary pressure regulating cavity.