Abstract: The production and processing technology of rigid polyurethane foam and its application in architectural field were reviewed. The foaming technology was mainly applied to external-wall interior insulation，sandwich thermal-insulating，and external-wall exterior insulation. Technology process for external-wall insulation was discussed in detail. The development trend of rigid polyurethane foam was forecasted.

Key words: rigid polyurethane foam, energy conservation in building, external-wall thermal insula-tion