In the field of camouflage, smart color-changing devices that can accurately adapt to different outdoor environments are a current research hotspot. However, traditional color-changing devices can be indistinguishable from the naked eye but cannot deceive advanced hyperspectral detectors, due to the visible reflectance spectrum difference between color-changing devices and the environmental background. Herein, a novel thermochromic paste is developed to achieve an accurate simulation of colors and reflection spectra of green leaves and soils. The paste displays a green color at < 30 °C and a soil-yellow color at > 30 °C, respectively. By further optimizing the dye ratio, the pastes can accurately simulate the reflection spectra of green leaves and soil. The spectral similarity between the pastes and green leaves and soils can be as high as 0.9674 and 0.9886, respectively. Moreover, the paste realizes reversible dynamic color change in 6 s and still possesses stable simulation after 100 times of cooling down and warming up. The thermochromic paste provides new insights for the development of multi-scene, multi-climate, and multi-band camouflage materials.