The invention discloses an electricity purchasing structure optimization analysis method based on amount price spatial constraint. The purchased electricity is grouped, the demarcation point, the electricity purchasing average price and the electricity purchasing amount of a low-electricity-price unit, a medium-electricity-price unit and a high-electricity-price unit are determined, an optimizable electricity purchasing amount is calculated, a channel capacity allowable maximum annual outside-province electricity purchasing amount and a province thermal power electricity purchasing ingredient electricity purchasing amount meet the upper limit and the lower limit of supervision requirements, an electricity purchasing structure optimization analysis model is established, an amount price spatial constraint value is calculated, a corresponding optimization rule is selected according to a judgment condition, the electricity purchasing amount is distributed again, and an optimized electricity purchasing structure is obtained. The method has the advantages that the electricity purchasing structure of a grid company is optimized through the method, government regulation requirements and a grid constraint condition are considered on the basis of the electricity purchasing structure optimization model of the amount price spatial constraint by taking purchasing cost minimization as a target function, a high electricity price component electricity purchasing amount is regulated and reduced to regulate and increase a low electricity price component electricity purchasing amount, and cost-reduction synergy is realized.