A freely assemblable toy track includes a plurality of guide rails and connecting pieces, each guide rail includes two independent strip rails (1) at the left and right, each connecting piece is configured as a frame piece (2) provided with a connecting part at a corresponding position of an inner frame edge for connecting with an end of each strip rail (1), ends of the two strip rails (1) are respectively connected to connecting parts of two frame pieces (2) to form a track body having a track surface with a middle portion hollowed, and a toy vehicle can locate left and right wheels on the left and right strip rails (1) exactly to run along the track. Based on a width of the toy vehicle, the frame pieces (2) with a corresponding width can be chosen to connect the strip rails (1), thus broadening the width of the tracks.