Abstract: For the Qingshen gas field deep horizontal well have the features of high temperature and easy breakthrough of gas, on the base of latex cement slurry system, high temprature stabilizing agent and conventional performance are optimized, and deep horizontal well system DHL-600 is developed. After evaluation of the indoor experimental results show that this system has the following features: conditions in the high temperature horizontal,it has low dehydration and no free water ;the density difference of slurry and cement is small;good stability;defend breakthrough of gas . Two deep gas horizontal wells, Qingshen gas field Shengshenping 1 well and Xushen 1-ping 1 well, which applied this system have no breakthrough of gas and good quality of well. Indoor experiment and field experiment show that this slurry system satisfed the demand of deep horizontal gas well cement quality.