In the present invention, diphenylphosphine oxide is derivatized, and prepared a phosphorus-containing flame retardant, which has no reactive functional groups, has better dielectric properties, and has high melting point, and upon combining with a vinyl compound, a resin composition is obtained, and a composite material having low thermal expansion ratio, high heat resistance, high glass transition temperature, and low dielectric constant and dissipation factor, can be made from the resin composition, and a laminate and printed circuit board having the properties of high glass transition temperature, low dielectric properties, halogen-free flame retardancy, low thermal expansion coefficient of the laminate, etc., can be made from the composite material.