The technical requirements of drilling fluid rheology test instruments under new drilling conditions are analyzed in this paper. The development and application of popular imported high temperature and high pressure rheometer are presented. This paper also introduces the research progress, main functions, technical advantages and application fields of the ultra-high pressure high-temperature and low-temperature drilling fluid rheometer Explore 97, which is independently developed in China, and takes it comparing with Fann iX77 rheometer in technology.