Abstract: It is often to encounter deterioration of tunnelling parameters, decrease of advance rates and so on during shield tunnelling in compound stratum with sand and gravel. Pre-reinforcement techniques, which are composed of two-component grouting on ground and pipe-roof grouting in tunnel, were adopted in phase Ⅲ of Chengdu metro line 1 in compound stratum with sand and gravel. The results show that cutterhead torque and thrust decrease and advance rates increase significantly during shield tunnelling after ground pre-reinforcement, these two pre-reinforcement methods both can improve shield tunnelling in the compound stratum with sand and gravel.