Modified phenolic resin for dry material, preparation method for modified phenolic resin and dry material

The invention provides a preparation method for a modified phenolic resin for a dry material. The method comprises the following steps of: a) reacting a phenolic compound with an aldehyde compound under the action of an acid catalyst to obtain a phenolic resin; and b) adding a modifier into the phenolic resin obtained by the step a), and performing reaction to obtain the modified phenolic resin for the dry material, wherein the modifier is rosin resin waste, coumarone-indene resin waste or epoxy resin waste. The invention also provides the modified phenolic resin for the dry material. The modified phenolic resin is obtained by modifying the phenolic resin by using the rosin resin waste, the coumarone-indene resin waste or the epoxy resin waste, and has the carbon yield of 20 to 30 percent at 800 DEG C. The invention also provides the dry material. Experiments show that the carbon yield of the modified phenolic resin prepared by the method is decreased from 50 percent to 20 to 30 percent, that all the compress