Three types of construction and application of external wall cladding systems containing rigid polyurethane insulation were introduced. Based on real building fire testing, the fire risk of exterior wall insulation of wet rendering systems, metal faced systems and curtain systems was compared and evaluated. Also, the influence of different construction and applications on fire performance of building exterior wall insulation systems was analyzed. The results indicate that compared with rendering systems, the performance of metal faced systems is not good, and a better performance can be achieved with good design of fire resistance construction to curtain systems.