The utility model relates to a novel outside-measuring-method hydrostatic test device. The novel outside-measuring-method hydrostatic test device is characterized in that one end of a total manual value is connected with a water source, and the other end of the total manual value is connected with the water inlet port of a booster pump; a temperature sensor is used for detecting the temperature of the water source; the water outlet port of the booster pump is connected with the water inlet of a one-way valve; the water outlet of the one-way valve is connected with the water inlets of a plurality of gas cylinder testing devices, and a pressure meter, one end of a pressure sensor and one end of a decompression solenoid valve are further connected on a pressure-bearing flexible tube between the water outlet of the one-way valve and the water inlet of a first gas cylinder testing device; and the other end of the pressure sensor, the control port of the decompression solenoid valve, the signal output end of the temperature sensor and the control port of the booster pump are all in signal connection with a computer control center, and the water outlet port of the decompression solenoid valve is connected with a drain tank through a low-pressure water pipe. According to the novel outside-measuring-method hydrostatic test device, by connecting a plurality of water jackets in series, the detection on a plurality of gas cylinders can be simultaneously realized, the detection cost is lowered, and the detection efficiency is improved, so that the device has the advantages of high automation, low cost and high efficiency.