The invention discloses a mass loss rate-based combustible liquid heat release rate testing system, and belongs to the field of testing systems used for determining combustible matter heat release rate in fire disaster developing processes. According to the mass loss rate-based combustible liquid heat release rate testing system, a thermal insulation exhaust fume collecting hood and a natural-type discharge flue are arranged on the upper part of a steel structured flame resistant glass restricted space; the center of the steel structured flame resistant glass restricted space is provided with a pool fire combustion platform which is arranged on a recording balance with heat exposure protection; the recording balance with heat exposure protection is connected with a microcomputer via a mass change collector; a temperature measuring thermocouple tree is arranged on the steel structured flame resistant glass restricted space via penetrating, and is connected with the microcomputer via a temperature data collector; a flue gas sampling probe is arranged on the center line of the natural-type discharge flue, and is connected with the microcomputer via a flue gas component analyzer . Processing and assembling of unit modules of the mass loss rate-based combustible liquid heat release rate testing system are simple; using method and operation processes are simple; and the mass loss rate-based combustible liquid heat release rate testing system possesses certain practical significance and economic application value.