The invention discloses a UHV DC protection field test method, device and system based on full process operation characteristic simulation, and the method comprises the steps: constructing an AC-DC primary loop model of a UHV DC transmission project and a DC control system equivalent model; performing model parameter configuration according to a required operation mode of the UHV DC transmission project; performing protection test configuration according to the functional logic of the tested protection; using a configured model for transient simulation operation calculation to obtain simulation operation data; extracting and processing the simulation operation data, and finally obtaining an AC analog simulation signal, a digital simulation signal, a switching value simulation signal and acontrol bus simulation signal which are outputted to a tested protection device; acquiring the protection exit action information of the tested protection device, and storing the information. The method can guarantee the testing reliability of the UHV DC protection function through the full process operation characteristic simulation of the UHV DC transmission project.