Compressed air purification device and control method

The invention discloses a compressed air purification device and a control method, relates to the field of compressed air purification, and aims to solve the problems that a traditional compressed air purification device generally reduces dead air accumulation by arranging a normally-released air path, a large amount of raw material gas is wasted, and meanwhile, the requirement of semiconductor production for high-quality compressed air cannot be met. Comprising a first adsorption tower and a second adsorption tower which are arranged in parallel, dead gas accumulated in the adsorption towers is removed through pressurization replacement, the mode that an original purification device removes the dead gas through a normally-released gas path is replaced, compressed air needing to be released in each regeneration period is only the compressed air amount needed by regeneration and pressurization replacement, and the regeneration efficiency is improved. A traditional replacement process is changed into a pressuri