The invention discloses a gathering and transportation skid-mounted device for gas injection and production of a salt cavern gas storage and a process method and belongs to the technical field of gas injection and production in a well field. A horizontal gravity type separator is connected with electric ball valves, a plug valve, a manual ball valve and a safety valve; the other end of a first electric ball valve is connected with an angle throttle valve; the other end of the angle throttle valve is connected with a second electric ball valve, and the other end of the second electric ball valve is connected with a wellhead; the other end of the manual ball valve is connected with an axial-flow check valve and an ultrasonic flowmeter, the other end of the axial-flow check valve is connected with a third electric ball valve, and the other end of the third electric ball valve is connected with the wellhead; an emptying valve is connected with an instrument joint and a fourth electric ball valve, the other end of the fourth electric ball valve is connected with a methanol injection port, and the other end of the methanol injection port is connected with the other end of the ultrasonic flowmeter; the other end of the plug valve is connected with a normal pressure blowdown drum; a methanol dosing device is connected with the methanol injection port. According to the gathering and transportation skid-mounted device and the process method, the injection and production efficiency of the gas storage is improved and the safety and the reliability of equipment in the gas storage are improved.