In order to solve the problem that powder hardeners for no-bake phosphate binder sand cause powder pollution, preparation of suspended liquid hardener has been studied in this paper. Orthogonal array L9(34) was selected to arrange the experiment. Under every factor and level an experiment was done, and suspension rate after four hours of the suspended liquid hardener was taken as experimental target. Results show that the addition of suspension agent and interaction between vector and suspension agent are significant factors at significance level α = 0.05. The best scheme is the one which contents 500g powder magnesia, 500g industrial alcohol vector and 20g SN suspension agent.