The invention discloses a method for measuring the content of suspension in the water extract of tobacco raw materials. The method comprises the following steps: (1) fetching the water extract of tobacco raw materials during the production process of paper-making reconstituted tobacco, adopting a Karl-Fischer method to measure the extract water content (Cw); (2) adopting a Brix degree meter to measure the Brix degree value (Sc) of the water extract; (3) calculating the content (Css) of suspension in water extract of tobacco raw materials according to a formula: Css(%)=100-Cw-Sc. The provided method has the advantages of short measuring time, high accuracy, high precision, good data repeatability, and high sensitivity, can be used to optimize the extraction, concentration, blending, and using technologies of tobacco raw material water extract, and is capable of improving the purity and quality of water extract.