A flow-through catalytic membrane micro-reactor (CMR) with Cu/ZnO/Al2O3 nanoparticles immobilized in porous membrane pores has been developed for hydrogen production by methanol steam reforming (MSR). The characteristics for CMR demonstrated Cu/ZnO/Al2O3 nanoparticles with almost 200 nm were successfully in situ immobilized in membrane pores. During MSR for hydrogen production in CMR by flow-through mode, hydrogen productivity of 500 mmol h-1 g-1 cat. and selectivity of 100% can be achieved under the condition of temperature being 360℃, molar ratio of water to methanol of 8.8 and gas hourly space velocity (GHSV) of 176.7 L g-1 h-1. Compared with the commercial fixed bed reactor, the hydrogen productivity in CMR is one order of magnitude higher, owing to MSR confined in the space of membrane pore with micro-scale. The methanol conversation rate of over 95% can be expected, if five sheets of CMR with thickness of 5 mm was assembly in series.