In order to improve the operation efficiency of air-source heat pump with enhanced vapor injection (EVI), a hot air–EVI air-source composite heat pump test bench was built. Rear air supply mode and a more uniform hood air supply mode were employed. The experimental results demonstrate that, compared to the rear air supply mode, the compressor power consumption in the hood air supply mode can be reduced by 1.6%–4.6%. Simultaneously, the heating capacity experiences an increase of 1.2%–4.6%, and the coefficient of performance is elevated by 3.1–8.7%. The exhaust temperature decreased by 1.74%. Moreover, the exhaust pressure in the hood air supply mode is decreased to a certain extent. These experimental findings not only offer a dependable air supply mode transformation scheme but also furnish essential data support for solar energy–EVI air-source composite heat pumps, showcasing promising applications in cold regions.