Massiveness and cost have impeded the promotion of absorption heat pump (AHP) system for a long time. An improved detachable plate falling film heat and mass exchanger (HMX) couple using lithium bromide (LiBr) and water as working fluids is proposed and a resulting prototype is experimentally assessed. The HMX couple can work as either a generator-condenser couple, or an absorber-evaporator couple in an AHP using LiBr and water as working fluid. In generator-condenser condition, overall heat and mass transfer coefficients of the generator were 0.607~1.008 kW×m-2×K-1 and 4.4×10-5~18.4×10-5 m×s-1 respectively, and overall heat transfer coefficient of the condenser varies from 0.372 to 1.466 kW×m-2×K-1; in absorber-evaporator condition, overall heat and mass transfer coefficients of the generator were 0.235~0.422 kW×m-2×K-1 and 0.7×10-5~1.5×10-5 m×s-1 respectively, and overall heat transfer coefficient of the condenser varies from 0.785 to 1.173 kW×m-2×K-1.