The construction optimization of Public Expenditure is worth to be studied. The paper mainly discussed the decisions of public expenditure in the perspective of capital investment, during the process of promoting the development of new high-tech industry, with ensuring the scale of governmental capital support. Based on the China's present situation, considering the different industry sections, the different industry development stages and the choice of creation and imitation, with reference to the experiences of financial expenditure in west countries, this paper studies the construction optimization of the public expenditure to promote the development of the new high-tech industry from both theory and policy practice.