Abstract: The low pressure cold spray is a new spray technology,which is different from the high pressure cold spray,in aspects of temperature,spraying distance,powder feeding rate and traverse speed as the main technology parameter.With the mixture of aluminium powder and the alumina powder as raw material and compressed air as the working gas,aluminium coating was prepared on Q235 steel substrate by low-pressure cold spray equipment.The effect of technology parameter on deposition efficiency of aluminum coating was studied and the microscopic structure and depositional mechanism of aluminum coating were investigated by means of optical microscopy,scaning electron microscope and X-ray diffraction.The results show that at 400℃,in spraying distance 25mm,feeding rate 30.6 g/min and traveres speed 4.0 m/min,the depositing efficency reaches the highest provided the pressure of working gas keeps under 0.6 MPa and aiumina as the ceramic phase may contribute to coating deposition.