The large number of distribution automation secondary equipment is the key object to maintain the safe and stable operation of the distribution automation system.The risk assessment process is established through the identification and continuous attention to the risk points of the secondary automation of the distribution automation.The average fault is calculated according to the state score of the equipment probability,then calculate the comprehensive risk loss and quantitative risk value.Taking the minimum cost of risk and the cost of maintenance as the optimization target,to construct the maintenance optimization model of the maintenance decision-making,and the scientific and reasonable sorting of the maintenance plan is given considering both the risk and the cost.Significantly reduce the cost of maintenance of secondary equipment and unreasonable maintenance may lead to the risk of failure,to achieve better operation and maintenance management of secondary equipment.