Central air-conditioning load of public buildings has become one of the most important peak load regulation objects of electric power company with the features of concentrated using time, large load capacity, various adjustable methods and little influence on customer, etc. Firstly, the technology architecture of large scale central air conditioning load participating in day-ahead peak load regulation is proposed. Then, aiming at minimumizing the compensation fees of electric power compay, considering the constraints of adjustable stragies, the total load, load deviation of peak load regulation, etc., the optimal dispatch model of central air-conditioning load for day-ahead peak load regulation are built, Lastly, taking Jiangsu Province demonstration project with non-productive air-conditioning load as an example, the dispatch schedule are obtained by CPLEX for morning, middle and evening peak load periods.