The invention discloses a testing system for a horizontal thrust of a handrail. The system comprises two clamping components; each clamping component includes two steel plates that are against the inner surface and outer surface of a side wall; through holes are formed in the two steel plates and one threaded steel bar penetrates the two through holes; nuts are arranged at the portions, arranged at outer sides of the two steel plates, of the threaded steel bar in a cooperative mode; and a vertical support is fixed at the inner end of each threaded steel bar. A counter-force cross beam is arranged between the two vertical supports. In addition, the testing system also includes at least one jack erected on the top of a support frame; the rear end of the jack is abutted against the counter-force cross beam; and the output end of the jack is abutted against a handrail. Besides, the testing system also includes at least one dial indicator that is erected on the top of a support frame and is arranged between the handrail and the counter-force cross beam. Therefore, the universality is high; rapid testing can be carried out at any floor; the construction efficiency is improved; and the cost is lowered.