Abstract: By means of normalized vacuum operation models and vacuum operation parameters, GDC（He） and siliconzation wall conditioning considerably improve the vacuum outgasing-rate, the base impurity concentration and the impurity-degassing rate during tokamak discharges. H recycle, wall fuelling, high parameter discharges, long-pulse discharges and the rapid restitution discharges after exposure air are successfully obtained. The excellent vacuum wall conditions is provided for demonstrating the LHCD、ICRH、ECRH、MBI、PI and NBI experiments. The mainly experimental results, include of the vacuum system, the control of outgassing-rate and recycle, the mass spectrum diagnosis and gas puffing are described. It will be benefit to the vacuum system development and operation in the HL-2A Tokamak.