The invention discloses a preparation formula and process for soft walnut chocolate. The formula comprises white granulated sugar, coca liquor pieces, cocoa butter, anhydrous butter oil, phospholipid, vanillin, an emulsifier, cocoa powder and walnuts. The process comprises the following steps: raw material checking and accepting, pre-treating, mixing, stirring, grinding, refining, heat preserving, temperature regulating, sizing, cooling, secondary protective layer loading, packaging and delivery inspection. According to the preparation formula, the anhydrous butter oil and skim milk powder are adopted to replace hydrogenated vegetable oil, so that a soft chewy feeling can show at the normal temperature. A protective film is pre-coated on the surfaces of the walnuts, so that two-way penetration of oil and water can be prevented, fat whitening can be avoided or delayed, walnuts are flatted, package of soft chocolate is facilitated, and the thermal stability and mechanical stability of a product are further enhanced; and after cooling and molding, one protective layer is coated on the product, so that influences of outside temperature and humidity on the soft chocolate can be isolated, frosting resistance can be enhanced, and multi-layer rich mouthfeel is achieved.