To understand the mechanism of ice layer growth and icing patterns on the surface of an aircraft engine inlet support plate, this paper used a cyclic low-temperature wind tunnel to simulate a high-altitude icing environment and conducted icing tests on three different composite material support plates: support plate A (composite material+metal edge), support plate B (composite material+coating), and support plate C (honeycomb composite material+coating+gas film holes and grooves). The test results show that the macro process of icing on the support plate surface can be divided into the adsorption, flow and freezing process of liquid water droplets hitting the support plate surface, which is affected by the liquid water content, average water droplet diameter, incoming flow velocity, temperature and duration. At a certain temperature and duration, the type of ice accumulation will gradually transition from clear ice to frost ice as the inflow velocity increases and the average water diameter decreases. The amount of ice formation and the detachment period decrease with increasing air volume and inflow velocity, but the detachment size of ice formation will not be affected after the air volume reaches a certain level. Overall, support plate C has the best anti-icing effect under the simulated two typical engine states of idle and intermediate thrust. The test results provide a reference for the anti icing design of the engine inlet support plate and provide detailed theoretical support for aircraft anti-icing and even air system optimization.