At present, China is becoming the world's largest door and window production and use market. In China, 500 million square meters of urban buildings, 600 million square meters of rural buildings and 700 million square meters of public buildings are completed every year. According to the proportion of doors accounting for 10% and windows accounting for 20%, together accounting for 30%, China has a door and window market of more than 500 million square meters every year. If the implementation of the national rigid energy-saving policy and the aging of the original doors and windows, in the next decade, China will successively have more than 11 billion square meters of doors and windows into the renewal period, and the market value of the reconstruction of the existing building doors and windows will reach 10 trillion yuan. Among them, the door and window market demand of high-end residential quarters and villas grows rapidly with an annual growth rate of more than 20%. The middle and high-end door and window market is becoming an explosive growth and another "big cake"....