The invention discloses a casing deformation well chemical packer segmented volume fracturing method. The casing deformation well chemical packer segmented volume fracturing method includes the steps that S1, the perforation position is determined and perforation is conducted according to stratum physical properties and logging data; S2, fracturing sequence is set according to stress intensity, the chemical packer use level and particle size combination are determined, and fracturing process parameters are designed; S3, a chemical packer is injected into a stratum to seal a crack opening and a perforation eyelet in a last fractured well section; S4, fracturing fluid is injected, at the same time, an in-seam supercharging agent is added, a first artificial crack is formed; S5, the chemical packer is injected to seal a first artificial crack opening and a perforation eyelet; S6, the fracturing fluid is injected again, at the same time, the in-seam supercharging agent is added, and a second artificial crack is formed; and S7, the chemical packer and fracturing fluid are repeatedly injected until fracturing of a casing deformation well section is completed. According to the casing deformation well chemical packer segmented volume fracturing method, segmented fracturing of a casing deformation well is realized, so that all well sections are adequately remolded, at the same time, the crack complexity can be improved by using the technology of in-seam pressurization, and the purposes of fracturing and stimulation are achieved.