The invention relates to an automatic natural environment continuous waterflow simulation test device, which comprises a water conditioning system, a dilution table, a biological test culture cabinet, a temperature and illumination control system, a data monitoring and acquiring system, a wastewater collection system, a water storage system and the like. Compared with the prior art, the automatic natural environment continuous waterflow simulation test device has the advantages that the device is evidently effective in natural waterflow dynamic environment simulation, stable in long-time operation, high in safety, simple in regulation, high in automation level, easy to demount for washing and easy to replace. Whole-course automatic monitoring, tracking and recording of the whole test process by a computer can be realized, reliability and stability in operation of the long-term waterflow test can be guaranteed by the test device, and the test device is applicable to GLP (good laboratory practice) tests of short or long toxicity of various relevant aquatic organisms published by the OECD (organization for economic cooperation and development) and the EPA (environmental protection agency).