In order to solve effectively the leakage phenomenon during drilling in high-temperature deep fractured formations，a new type of high-temperature resistant rigid sealing agent HTD-2 was developed，and it was compounded with modified inorganic mineral fiber GXW-1 and elastic sealing material TDS-2 to form a composite sealing material. The performance of the plugging material was evaluated through temperature resistance performance experiments，crack sealing experiments，high-temperature and high-pressure sand bed sealing experiments and compatibility experiments with drilling fluid. The results showed that the temperature resistance performance of HTD-2，GXW-1，and TDS-2 was significantly better than that of walnut shell. Under high temperature and pressure conditions，a single sealing material could not achieve good sealing effects on cracks with different size， while composite sealing materials had better sealing effects. The composite sealing materials，composes of 8% HTD-2 + 1.5%GXW-1+6% TDS-2，could make the 30 min leakage of 0.5—2 mm cracks be reduced to below 100 mL，and the pressure bearing capacity of the sealing layer was greater than 10 MPa. The addition of composite plugging materials could make the drilling fluid have good sealing effect in different sizes of rock debris sand beds，with a 60 min invasion depth of only 9.3 cm for 0.85—2 mm sand beds. In addition，the composite sealing materials had good compatibility with drilling fluids. The in-site application results showed that when using drilling fluid with composite plugging materials for in-site construction，there was no significant leakage phenomenon during the drilling process of GX-1 well，and the drilling process was smooth，effectively improving drilling efficiency and quality. This composite sealing material is suitable for promotion and application in sealing construction operations in high-temperature and deep fractured formations.