To investigate the influence of cottonseed oil mass fraction on the rheological properties and anti-vibration performance of site-mixed emulsion explosive matrix, samples of site-mixed emulsion explosive matrix with different cottonseed oil mass fractions were prepared. A rotational rheometer, HY-5A rotary speed-regulating vibrator, and water dissolution method were used to study the rheological properties and anti-vibration performance of the site-mixed emulsion matrix. The results show that when the mass fraction of cottonseed oil is not more than 2.5%, the viscosity of the site-mixed emulsion matrix increases gradually. In terms of the temperature environment of the pipeline of on-site mixing trucks, the viscosity of the emulsion matrix can meet the pumping requirements. The elastic modulus and cohesion increase gradually and then remain nearly stable. The anti-vibration performance first increases and then decreases, and when the cottonseed oil mass fraction is 2.0%, the anti-vibration performance is the best.