Abstract: Abstract: In the new solar greenhouse with walls without heat storage function and a plastic tunnel covered with thermal blanket without walls (PTET), auxiliary heating measures should be taken to make up the lack of heat supply caused by canceling the heat storage and heat release function of the rear wall. At noon in winter, the temperature in greenhouses and plastic tunnels is higher, indicating that the air is rich in heat energy. It is an effective way to realize low-carbon and energy-saving production of horticultural facilities by using the excess air heat energy for night heating. Therefore, a thermal collecting and releasing developed with fan-coil units and heat storage pool for heat collection (TSFU), has been developed. But the heat collection capacity of this system is only (454.6±55.9) MJ and 142 MJ in sunny and cloudy days, respectively. Therefore, on the basis of this system, a heat pump is added, thus forming a combined heat collection system with fan-coil units and heat pump (FUHPS), aiming at improving the heat collection capacity of TSFU. FUHPS has three heat collection modes: fan-coil units heat collection mode (fan mode); fan-coil units+heat pump mixed heat collection mode (mixed mode); Combined heat collection mode of fan-coil units+heat pump (combined mode). The combined mode of sunny and cloudy days achieves (763.9±17.1) and (519.7±30.5) MJ respectively,which was higher than (439.3±4.7) and (223.1±8.9) MJ in the fan mode (which is the same as the heat collection operation mode of the TSFU), which are increased by 73.9% and 132.9% respectively. These results prove that the heat collection capacity of the system is significantly increased and the design is correct and feasible. In order to speed up the popularization and application of this new technology in solar greenhouses without heat storage function and plastic tunnels covered with thermal blanket, a design and calculation method of FUHPS which can be used in different types and specifications of horticultural facilities was provided. The design method mainly includes the calculation of greenhouse heat load, the selection of heat pump, the selection of submersible pump in heat collection pool and heat storage pool, the calculation of heat storage pool volume and the determination of the number of fan-coil units, etc. This method can be used to calculate the main parameters of the FUHPS for different greenhouses. Taking its practical application in 500 m2 solar greenhouse without heat storage function as an example, it was calculated that at –10℃ at night, in order to keep the indoor temperature not lower than 15℃, 10 FNH fan-coil units were needed, the rated input power of heat pump was 15 kW, the flow rates of submersible pump in heat collection pool and submersible pump in heat storage pool were 15 and 14 m3/h respectively, and the volume of heat storage pool was 19.8 m3. The total investment in the early stage of this system is 74,000 yuan. On sunny days, assuming that 400 MJ of heat needs to be collected, the heating cost of gas-fired hot-blast stove is 114.8%, 72.3% and 49.1% higher than that of fan mode, mixed mode and combined mode of this system, respectively. It can be seen that although the early stage investment cost of this system is relatively high, the operating cost is relatively low.