Abstract: As for offshore HTHP (high temperature and high pressure) well testing technologies, the main issue in ground process is that hydrate is formed and blocks the pipelines, resulting in a series of difficulties, e.g. flow overpressure, high-temperature seal failure, ground process erosion, leakage and high-heat radiation caused by burning. In order to efficient and safe testing operation, a set of ground processes for offshore HTHP well testing was designed based on the HTHP testing risks, combined with the spatial restriction of offshore platforms. Then, the safety control technology for the testing process of offshore HTHP wells was developed. Based on multi-node monitoring, the testing performance data is monitored and recorded in real time, accidents are prevented and complex situations are dealt with promptly. The safety of testing operation is improved by allocating equipments and pipelines safely. The emergency shutdown barrier of ground process and the emergency release process of testing are set up to solve effectively the process pressure building and overpressure caused by pipeline blockage by cutting off the source of high-pressure formation fluid in time in the case of leakage. The spray cooling system is 3D deployed to prevent the high-heat radiation caused by high-yield burning from damaging the equipments and personnel on the platform. This technology is well applied in the field, and it should be popularized further.