An electronic bead string includes a main bead, a plurality of secondary beads, a displacement sensor, a memory, and a processor. The main bead and the secondary beads are strung together to form a bead string. The displacement sensor is fixed in the main bead to output two-dimensional displacement signals, the memory stores the two-dimensional displacement signals, and the processor determines whether a rotation cycle of the electronic bead string is an approved rotation cycle according to the two-dimensional displacement signals.