The invention discloses a series-connection frostless air source heat pump system based on regenerated heat recycling. The series-connection frostless air source heat pump system comprises a heat supply heat pump loop, an auxiliary heat pump loop, an air loop and a solution loop. According to the series-connection frostless air source heat pump system, two heat pump system bodies are in series connection to run; an auxiliary heat pump is used for absorbing heat from air and heating a regenerated solution; a heat supply heat pump is used for providing heat for the indoor environment; and on one hand, dehumidification is conducted through the solution, so that safe and frostless operation of the heat pump system is achieved, and on the other hand, sensible heat and latent heat in regenerated air are recycled through a closed air cycle loop, so that regeneration efficiency of the solution and operation efficiency of the system are greatly improved. The large temperature difference generated in the heat pump operation process in winter is distributed into two heat pumps, so that the compression ratio of each compressor is reduced, and stability and energy efficiency of system operation are improved; and in addition, continuous heat supply conducted in the heat pump operation process is guaranteed, and thermal comfort inside a room is improved.