Based on SMW engineering method, a new HCMW engineering method for foundation supporting was developed, with the advantages of good anti-bending ability, strong watertight sealing, smaller surrounding soil disturbance. Based on the engineering practice, this paper studies the supporting law and effect of HCMW method in the aspects of working condition mechanics analysis, surface settlement, anti-overturning stability, overall stability, heave resistance stability coefficient and so on. The result shows that the horizontal displacement of supporting structure has been significantly changed after bracing, with a gradually decreasing trend from the surface to the bottom of the pit. With the soil's unloading in the excavation area, collateral supporting soil pressure decreases, resulting in a decrease in the displacement of the soil in the lower part of the foundation pit, which generally occurs between 0 and 2 m from the bottom of the pit. The total settlements around the foundation pit and their distance from pit rim present a parabolic shape. The maximum settlement is 18mm, which occurs 5.6m away from the pit rim; the anti-overturning stability, overall stability and heave resistance stability coefficient of the foundation pit are calculated, the homologous values being 1.974, 1.386 and 2.793, which are all greater than the standard safety factors in the specification and meet the safety requirements, indicating that the HCMW method has a better supporting effect.