In the present retrofit of DCS(distribute control system) in Fengcheng power plant, the soft measurement method is applied, and the analogue quantity feedback of the actual position is accurately obtained by using the opening, closing and stopping signals of motor drived valve of main feedwater. As a result, the production and labour cost are reduced, as well as some intuitionistic and reliable data are provided to operators. Furthermore, the BIR(boiler input rate) dynamic feed-forward control idea which is adopted in the FTCCS(furnace-turbine coordinated control system) of 600 MW supercritical unit, is applied in 300 MW units successfully so that load response ability is raised and control quality improved. The successful application of the control strategies not only has great significance to the production management of the company, but also provides useful reference for the optimization design of similar project.