A channel estimation device and method for an orthogonal frequency division multiplexing (OFDM) system for receiving OFDM symbols to generate channel estimation information is provided. The channel estimation method includes: obtaining a portion of pilot signals from a plurality of pilot signals as a first pilot set according to corresponding positions of the pilot signals in the OFDM symbols; estimating a first estimation factor by calculating the pilot signals in the first pilot set in a first direction; estimating a second estimation factor by calculating the pilot signals in the first pilot set in a second direction; obtaining a pilot signal estimation result according to the first estimation factor and the second estimation factor; and obtaining the channel estimation information according to the pilot signal estimation result.