Further analyzing the implied condition in Solow model, it is concluded, first, there is a definite relationship between the total output of the regional economy and its total capital investment, and secondly, there is an optimal economic growth path only when the input-output coefficients in all industries are equal. So, by estimating the corresponding input-output coefficients each year, the amount of fund demand to reach the goals of economic development could be obtained. This paper works on the case of tourism development from 2011 to 2020 in Fujian Province to illustrate the above points.