The invention discloses a skid-mounted rocket tank pressure annunciator flight vacuum environment simulator which is composed of a vacuum chamber door, a vacuum chamber, a vacuum gauge, a candlestick, a vacuum pump, a platform dolly and the like. The simulator is used for an upper stage rocket tank pressure annunciator and simulating a vacuum condition for the upper stage rocket tank pressure annunciator operating outside the earth's atmosphere. According to the invention, circuit insulation and sealing problems are solved. When the simulator operates, vacuum degree inside the vacuum chamber is better than 1 Pa. The pressure annunciator has a simple installation structure and is convenient to dismount and maintain. Vacuum cement and aluminium bars are used for sealing of pressure annunciator cables passing through the wall of the vacuum chamber. The structure is simple and easy to realize and is good in vacuum seal effect and low in cost. By integrating the vacuum chamber and the vacuum pump into one platform dolly, the structure of the system is compact and the vacuum-pumping effect of the vacuum chamber is enhanced. In addition, the integral body is convenient to move, and maintainability of the system is improved.