The invention discloses a phase obtaining device for OFDM communication systems, comprising a lookup table, a clock counter, two shifters, three reversers and three accumulators, where horizontal coordinates of some point are inputted into the first shifter and vertical ones are inputted into the second shifter; the output of the first shifter is inputted into the first reverser and that of the first reverser is inputted into the first accumulator; the output of the second shifter is inputted into the second reverser and that of the second reverser is inputted into the second accumulator; theoutput of the clock counter is inputted into the first shifter, the second shifter and the lookup table; the output of the lookup table is inputted into the third reverser and that of the third reverser is inputted into the third accumulator, and that of the third accumulator is the obtained phase. On the condition of not reducing accuracy, it implements a phase obtaining hardware device with lowcomplexity, low hardware resource consumption and high accuracy.