In this paper, a three-dimensional flow visualisation method based on transmission phase measurement deflectometrywavefrontdetectionisproposed. Thedirectiondeflectionoflightafterpassingthroughtheflowfieldreflects thechangeofrefractiveindexinsidetheflowfield.AccordingtothereverseHartmannwavefronttestingmodel, thethree-dimensional reconstruction of the flow field is carried out by using the back projection reconstruction technology by simultaneously recording the deflection of light ray from multiple viewing angles. This paper introduces the measurement principleandalgorithmindetail, andverifiesthethree-dimensionalreconstructionofthetransientflowstructureinthehigh-speedflowfieldthroughnumericalsimulation.Therootmeansquareerror(rms)ofthereconstructionerroroftherefractive index field is about 0.19 kg/m3, which verifies the correctness of the method. The results show that this method has the advantagesofnon-contactquantitativemeasurement, highaccuracy, simpledeviceandlowcost.