The invention discloses an on-site mixed emulsion explosive decoupling charge method and a side slope forming blasting method. Diameter constraint of a charging hose in a blast hole is used for achieving presplitting blasting or smooth blasting blat hole decoupling charge structures and linear charge density control needs, meanwhile, through the on-site mixed emulsion explosive foaming degree, andthe input amount control of an emulsion substrate, the liner charge density in the blast hole and the charge length adjusting in the blast hole can be achieved, needs of charge parameter fine adjustment according to the actual blasting effect in the subsequent construction can be met, the mechanical degree of charging can be improved, the aim of simply and rapidly making decoupling blasting cartridges and charge blasting construction can be achieved, construction auxiliary consumable items are few, and construction cost is greatly reduced.