The invention discloses a walking-replacing and fitness multipurpose electric bicycle. A travelling mechanism, a driving mechanism and a main controller are arranged on a bicycle frame assembly; the travelling mechanism comprises a front rolling shaft and a rear rolling shaft which are arranged in the middle of the bicycle frame assembly and further comprises a travelling conveying belt connected with the front rolling shaft and the rear rolling shaft; one end of the rear rolling shaft is provided with a rear shaft gear, and an assistance sensor corresponding to the rear shaft gear is arranged on the bicycle frame assembly; the driving mechanism comprises a driving motor arranged at the rear end of the bicycle frame assembly, a first gear arranged at one end of the driving motor and engaged with the rear shaft gear, a second gear arranged at the other end of the driving motor and a rear wheel flywheel which is arranged on a rear driving wheel and coaxially rotates with the rear driving wheel. The rear wheel flywheel is connected with the second gear through a chain, and meanwhile the driving motor and the assistance sensor are in electric connection with the main controller. The walking-replacing and fitness multipurpose electric bicycle has the advantages that a cooperative effect is formed between travelling movement and driving, and the purposes of walking-replacing and fitness are achieved.