Abstract: In order to solve the problem that the displacement accuracy of linear displacement mechanism is too high in traditional white light interferometry, this paper proposes a full-field heterodyne white light interferometry. The technology mainly uses the white light interference signal with difference frequency as the light source to realize the high-precision detection of the coherent peak position under the conditions of large push step and low push precision. In this paper, the mathematical model of white light heterodyne interference is established firstly, and then the overall system design scheme is proposed according to the light intensity signal characteristics provided by the mathematical model. Then the feasibility of the measurement scheme is verified by experiments. At the end, theoretical analysis and data comparison are carried out for the influence of various errors on the calculation accuracy of the algorithm. The results of error analysis show that the white-light heterodyne interferometry technology provides higher measurement accuracy and better anti-interference performance, effectively reducing the strict dependence of traditional white light interferometry on the accuracy of linear displacement mechanism, and is an optical free-form surface detection technology. More solutions are available.