The invention discloses biomass synthetic resin and method for producing a coconut palm mattress by use of the biomass synthetic resin as an adhesive. The biomass synthetic resin is obtained through the following steps: mainly taking biomass synthetic resin albumen powder, modified starch and modified cellulose as main raw materials, preparing a chain extender as a solution, adding the main raw materials to react at a normal temperature, and then heating to perform the reaction, cooling after the reaction, orderly adding a cross-linking agent, a tackifier and an inorganic filler to stir and react to obtain a product biomass synthetic resin. The method for producing the coconut palm mattress by use of the biomass synthetic resin as an adhesive is as follows: firstly treating bundled coconut palm raw material into the coconut palm fiber, carding through a coconut shred carding machine, and then weaving as a curtain through a lapping machine; sizing and folding the curtain by use of a spraying sizing system to obtain a coconut palm blank; and then performing the prepressing molding, hot-pressing molding and after-treatment in order to obtain the product coconut palm mattress. The biomass synthetic resin adhesive disclosed by the invention is virtually formaldehyde and organic volatile matter-free, and the harm to the human body health in the use process is avoided.