•Influencing factors on water spray cooling in non-boiling area are analyzed.•The influence of evaporation intensity on spray cooling performance is analyzed.•The optimal angle between aircraft and the gravity is provided for spray cooling.•Experimental dimensionless correlations of Nusselt number are developed. In this paper, the performance of a water spray cooling system is investigated experimentally. The influence factors including the nozzle atomization effect, spray height, heat flux, inlet pressure and gravity angle are discussed. Results show that under the same operating conditions, the main influencing factor is the spray mass flow rate involved in heat transfer. Heat transfer performance becomes better with the increases of mass flow rate. For the same nozzle, the best heat transfer performance appears under the critical height. The performance of spray cooling is improved with the growth of inlet pressure and evaporation intensity under the same inlet temperature. Furthermore, the heat transfer performance is closely related with the gravity angle. The best heat transfer performance appears when the gravity angle is between 30° and 120°. Heat transfer performs the worst when the gravity angle reaches 180°. Besides, experimental dimensionless correlations of Nusselt number are given in non-boiling area with water coolant.