The invention relates to a vertical type cross-flow air conditioner with a top air outlet function, and a control method. The vertical type cross-flow air conditioner with the top air outlet function comprises a shell, a heat exchanger assembly, a volute assembly, a top air outlet assembly and a front air outlet assembly, wherein the shell is vertically arranged and is of a long cylinder structure, and the heat exchanger assembly, the volute assembly, the top air outlet assembly and the front air outlet assembly are mounted in the shell; the top air outlet assembly is mounted at the top of the interior of the shell, and part of air flow, subjected to heat exchange through the heat exchanger assembly, in the shell is exhausted from the top; the volute assembly is located below the top air outlet assembly, and the front air outlet assembly is mounted in the volute assembly; a mounting support is fixed to the inner side wall of the shell, and the top air outlet assembly is fixedly mounted at the upper end of the mounting support; and gaps are reserved between the lower end of the mounting support and the upper end of the volute assembly as well as between the lower end of the mounting support and the upper end of the heat exchanger assembly. According to the vertical type cross-flow air conditioner with the top air outlet function, and the control method, the mounting support is fixed to the inner side wall of the shell, and the gaps are reserved in the lower end of the mounting support, so that the whole top air outlet assembly is borne by the shell, and the situation that the performance of the whole air conditioner is affected due to the fact that the volute assembly or the heat exchanger assembly at the lower end of the mounting support is overloaded is avoided.