The invention provides a preparation method of a steel-backed copper-based bearing bush copper coating. The preparation method comprises pretreatment: removing oil and rust on the surface of a steel bearing bush base, carrying out sandblasting roughening pretreatment and cleaning the surface of the base through a cleaning agent, preheating: preheating the steel bearing bush base and keeping the temperature in the steel bearing bush base in a range of 100-150 DEG C, and spray coating: spray-coating the steel bearing bush base with high-aluminum bronze powder through a spray gun moving along a longitudinal direction. The bearing bush obtained by the preparation method retains the strength and rigidity of the bearing bush and a high oil storage rate belonging to the material having high porosity.