The invention discloses a natural gas hydrate formation drilling simulator, comprising a hydrate core simulation system, a drilling system, a drilling fluid injection system and a drilling fluid treatment system, wherein the hydrate core simulation system comprises a hydrate formation simulation wellbore, an artificial core, a bath jacket and a low temperature water bath; the drilling system comprises a holder, high pressure adapting equipment, hydraulic equipment and drilling equipment; the drilling fluid injection system comprises a mud tank, a drilling fluid flow meter, a mud pump and a relief valve; the drilling fluid treatment system comprises a high pressure desander, a back pressure and overflow control system, a gas-liquid separator, a dryer, a gas meter, a liquid flow meter and a mud treating tank. The simulator can carry out relevant simulation experiments on various underground working environments, and has the characteristics of convenience in operation and simple structure, and thus laboratory test data are provided for assessment of natural gas hydrate drilling safety control and establishment of drilling schemes.