The invention relates to a cladding tube internal pressure bursting test device. The device comprises a first medium source, a second medium source, a vacuum heating device, a cladding tube arranged in the vacuum heating device, a pressure medium conveying pipeline, at least one temperature probe which is arranged on the vacuum heating device and detects the cladding tube temperature, a pressure release device arranged on the vacuum heating device and a control device, wherein the pressure medium conveying pipeline is connected with the first medium source and the second medium source and communicated with the cladding tube and conveys pressure media to the cladding tube, and the control device is connected with the vacuum heating device and the pressure medium conveying pipeline and controls the vacuum heating device to heat and controls the pressure medium conveying pipeline to convey the media; the control device comprises a first mode of controlling the pressure medium conveying pipeline to convey the first media at first temperature and a second mode of controlling the pressure conveying pipeline to convey the second media. The cladding tube internal pressure bursting test device can be used for simulating and measuring the loading capacity of the cladding tube in the working condition that a nuclear power plant has an accident in the high temperature and high pressure environment.