The invention discloses an acute inclined large and thick ore body chamber horizontal layout method, belongs to the technical field of underground ore chamber design methods and is applied to ore chamber layout and parameter calculation of an acute inclined large and thick ore body span structure system. According to the technical scheme, the method comprises the following steps: horizontally dividing an ore body into a three-span two-step hyperstatic arch truss structure stress system according to ore chambers of a first step and a second step; calculating axis force distribution under different hyperstatic conditions; calculating support base counter force of the two-step hyperstatic arch truss structure stress system and axis force distribution of a rod in the system; calculating the relationship of a single-span half-span value 1 and a two-step ore chamber width b according to equations, carrying out layout design on the ore chamber, and analyzing stability of ore columns of the ore chamber; calculating the relationship of the single-span half-span value 1 and the height h of a stope roof rock tensile region according to equations, and analyzing tensile damage of a stope roof.By adopting the method, the ultimate balance theory and the Mohr-Coulomb theory are adopted, structure parameters of the ore chamber are calculated, the stability of the ore chamber is analyzed, and reasonable layout in the ore chamber can be achieved.