The invention relates to a manufacturing process of an environment-friendly carton spacer plate. The manufacturing process comprises the process steps that 1, sludge is filtered, wherein collected paper making sludge undergoes filtration and impurity removal; 2, the sludge is concentrated, wherein the paper making sludge treated in the step 1 is input into a sludge sedimentation tank, cationic polyacrylamide accounting for 1-2% of the absolute dry weight of the paper making sludge is added into the paper making sludge, stirring is performed for 120-150 seconds at the stirring speed of 250-300 r/min, and then sludge gravity concentration is performed; 3, the sludge is dewatered, wherein the concentrated paper making sludge is dewatered by adopting a band type sludge filter press; 4, slurry is made; 5, the filter press is formed; 6, squeezing and drying are performed. The paper making sludge is used as a raw material to make the carton spacer plate and is resourcefully utilized, the problem of second pollution the paper making sludge is thoroughly solved, and land resources are saved. In addition, the manufacturing process is simple and low in production cost.