Abstract: A five-storey brick-concrete office building was planned to be rebuilt into shopping mall，and the wall of the 1st and 2nd floor would be dismantled to form a large space． Based on the test appraisal and the structure forced characteristics，the holistic hidden steel frame structure system strengthening scheme and tri-connection structure strengthening method were used． With the holding-wall beam to the key member of the structure，the monitoring results showed that the result of strengthening achieved the request of the design，and the building was safe in use up to now．