In present work we carried out multi-polytropic model of the Sun with a radially variable and smooth polytropic exponent. We found the new equation for this kind of multi-polytropic structure which we solved out using a numerically using as imput suitable functions for the variable exponent as well as for the coefficient of proportionality in the equation of state. The agreement between the distribution of pressure and density of our model en that given by the solar standard model of Bahcall, Serenelli, and Basu is very good with small discrepances in the convective region. Thus this model has a potential in dealing with perturbative application like those leading to heliosysmology analysis.