The utility model discloses a test instrument for gas emission upon water contact, including testing arrangement, base device, gas -collecting device and monitoring device, testing arrangement includes water bath, retaining cup, reaction bulb, heating pipe, water pump and water injection mechanism, gas -collecting device includes pipeline set piece, gas collection motor, gas collection mechanism,monitoring device includes inductor, power module, touch -sensitive screen, control device and mainboard, the touch -sensitive screen passes through the mainboard with control information to be transmitted for each inductor and control device, and behind the information processing that the mainboard detected the inductor, line display is advanced for the touch -sensitive screen to the transmission, the utility model provides a test instrument for gas emission upon water contact and application method adapt to the check out test set of era development, come to carry on that dangerous characteristic detects and be categorised material or mixture.