The invention belongs to the technical filed of organosilicon preparation, and discloses a cation polysiloxane Pickering emulsion with low soap and excellent stability, a preparation method and an application thereof in a paint field. The method is characterized in that inorganic nanoparticles and a cationic surfactant form a primary emulsion, then the primary emulsion is polymerized with an organosilicon monomer and an alkalescence catalyst to obtain the cation polysiloxane Pickering emulsion. The prepared cation polysiloxane Pickering emulsion uses the cooperation emulsification effect of the inorganic particles and the cationic surfactant, and linear cation polysiloxane Pickering emulsion can be obtained by initiation of ring-opening polymerisation under alkaline condition. The obtained cation polysiloxane Pickering emulsion has low emulsifier content and excellent emulsion stability, a disperse system of the emulsion is aqueous environment, the emulsion has the characteristics of high wetability, good ageing resistance, excellent coating performance, and mild performance, has the advantages of simple production technology, environmental protection and obvious cost advantage, and can be widely used in the paint filed, especially waterproof paint field.