This paper aims at building the endogenous dynamic evolution model between two systems based on the traditional agriculture operation,which,through the comparative analysis on both steady equilibrium and static equilibrium,shows that the double helix dynamic evolution of both capital input efficiency and agricultural scale efficiency leads the family farm system innovation.The expansion of family farm scale generates continuous effects on the labor force shift in agricultural sector.The enhancement of family farm capital input efficiency forms siphonic effect on output efficiency and labor inc...