Abstract: This paper present a new method which diseribes colloidal particles model and calculation of any shape colloidal particles interaction enrgy in dispersed system. we choose a coordinate origin inside a convex body which represented a colloidal particle, take coordinates of direction θ and (φ)(0≤θ≤π, 0≤(φ)≤2π).For any direction (θ,(φ)), there is one and only one plane which is in cotact with the convex body and whose normal from the origin is in the direction (θ,(φ)). This plane is named the supporting plane in the direction (θ,φ). This plane is named the supporting plane in the direction (θ,φ). When a convex body A (or whose parallel body) moves around convex body B (or whose parallel body), assume interaction energy between two supporting planes of A and B can calculate from the DLVO theory, then interaction free energy of two any shape convex bodies is equal t surface inegral of interaction energy of the supporting planes over the whole surface of the convex body (or whose parallel body). A simple formula of interaction free energy of two identical spherical colloidal particles at constant surface potential has obained, namely,
V_(WJZ)=V_D·(1-(κη+α_1)/(β_1κa))
where V_(wjz) is our result, V_D is result of Derjaguin method, κ is Debye-Hükel parameter, a is radius of particle and ρ is the shortest distance between two identical spheres, α_1 and β_1 are a complex function of κρ. The α_1 and β_1 can determinate by way of power series method. we calculate interaction energy of two identical spherical particles use of values of α_1 and βin Table 2. Comparison of present result with those of ML, OCHW and computer result, when κa>10 it is better than result of ML, commensurates with result of OCHW.