NOVELTY - Parameter combination measuring device for producing methane comprises a shell body, a displaying device (2), a keyboard (3) and a circuit unit. The displaying device and the keyboard are arranged on the shell body, and are used as a controlling signal output and a controlling signal input for connecting with the circuit unit. The circuit unit comprises e.g. a central processing unit (1), a pool liquid pH-measuring circuit, a methane concentration measuring circuit (7), a hydrogen sulfide gas concentration measuring circuit (9) and an analog-to-digital (A/D) converter and interface circuit.    USE - The device is useful for producing methane.    ADVANTAGE - The device: exhibits high integration, measuring accuracy and stability; allows intermittent measurement of the parameters during the methane production, and controls data connection via connecting it to a control local area network through the connection interface, and thus it is cost-efficient; and is convenient to use.    DETAILED DESCRIPTION - Parameter combination measuring device for producing methane comprises a shell body, a displaying device (2), a keyboard (3) and a circuit unit. The displaying device and the keyboard are arranged on the shell body, and the keyboard and the displaying device are used as a controlling signal input and a controlling signal output for connecting with the circuit unit. The circuit unit comprises: a central processing unit (1); a pool liquid pH-measuring circuit; a methane concentration measuring circuit (7); a methane concentration lower explosive limit (LEL) percentage concentration measuring warning circuit, which is a methane LEL percentage concentration measuring warning circuit; a hydrogen sulfide gas concentration measuring circuit (9); and an analog-to-digital (A/D) converter and interface circuit. The pool liquid pH-measuring circuit, the methane concentration measuring circuit, the methane LEL percentage concentration measuring warning circuit and the hydrogen sulfide gas concentration measuring circuit are used as a parameter measuring signal terminal of the parameter combination measuring device for collecting the corresponding parameter signal. The signal output ends of the pool liquid pH-measuring circuit, the methane concentration measuring circuit, the methane LEL percentage concentration measuring warning circuit and the hydrogen sulfide gas concentration measuring circuit are respectively connected with the corresponding signal input end of the A/D converter and interface circuit. The control signal output end of the A/D converter and interface circuit is connected with the input/output (I/O) terminals of the central processing unit.    DESCRIPTION OF DRAWING(S) - The figure shows a schematic block diagram of the parameter combination measuring device (drawing includes non-English language text).    Central processing unit (1)    Displaying device (2)    Keyboard (3)    Methane concentration measuring circuit (7)    Hydrogen sulfide gas concentration measuring circuit (9)