An important and efficient way for forest biomass utilization is to prepare the phenol-formaldehyde resin adhesive by taking bio-oil from its' pyrolysis-liquefied as a clean chemical raw-materials. The technical progress in pyrolysis liquefaction of forest biomass and preparation of environmental adhesive with bio-oil was introduced. The approaches of bio-oil usage were comparatively analyzed. By taking the process capacity of 4000t in Hebei Province as example, equipment composition and investment scale of biomass pyrolysis liquefaction production line, the cost of bio-oil, and economic benefits of phenol-formaldehyde resin with bio-oil instead of phenol were analyzed and discussed. Analysis shows that the investment of forest biomass pyrolysis liquefaction project with the capacity of 4000t in Hebei Province is about 2.5 million RMB Yuan, and the actual production cost of bio-oil is about 1200 RMB Yuan per ton, the direct economic benefit when all bio-oil are used to prepare the phenol-formaldehyde resin adhesive is up to 3.3 million RMB Yuan per year. The project of forest biomass pyrolysis liquefaction for the preparation of adhesive is a kind of advanced and mature technology that has significant economic benefits and with good prospects for the development and applications.