The utility model discloses a medicament injection device and a medicament injection system for a high-pressure sulfur-containing gas well. The medicament injection device comprises a medicament injection barrel, the first hydraulic control valve is connected to one end of the medicament injection barrel and used for being communicated with a wellhead; the four-way joint is connected to the otherend of the medicament injection cylinder; wherein the pressure release valve is connected to the open end of the four-way connector and used for being communicated with an emptying device, the injection valve is used for being communicated with a liquid medicament injection device, and the second hydraulic control valve is used for being communicated with a solid medicament feeding device. According to the medicament injection device, the first hydraulic control valve is arranged for opening and closing, so that the operation time is saved, and the working efficiency is improved; and by arranging the medicament injection barrel, the accommodating space of injected medicaments is increased, and the amount of the injected medicaments at a time is increased. And in the process of repeatedly operating the valve, due to the adoption of the automatically-controlled valve, leakage caused by abrasion of the valve can be avoided, and the well control risk is reduced.