Phosphorus recover from wastewater can not only reduce the unbearably impacts of excessive nutrient discharge on environmental systems, but also favor the reuse of phosphorus resource. Based on the mechanism as well as technical analysis of major phosphorus recover techniques including struvite precipitation and wetland substrate adsorption, a novel magnesium slag packed wetland filter and corresponding procedures are proposed, which aims to reduce the dependence of using magnesium contained chemical reagent as magnesium sources for struvite precipitation, and improved the accumulation and recover performance of struvite precipitation within porous wetland substrate. Results from a preliminary experiments indicated that magnesium slag particles with 2mm in diameter can supply magnesium for struvite precipitation and phosphorus adsorption, which probably confirmed the potential of phosphorus recover in magnesium slag packed wetland filter. The proposed phosphorus recover technology is free of secondary pollution and solid waste generation; phosphorus saturated (mainly due to struvite precipitation and adsorption) magnesium slag particles can be used as phosphorus fertilizer, and thus partly solved the traditional problem of disposing saturated substrate with low phosphorus contents. It is implicated that magnesium slag packed wetland filter can be regarded as a promising solution to recover phosphorus from industrial as well as domestic wastewater.