A collision detection method for a radio-frequency SIM card with low-frequency magnetic communication comprises: transmitting by a card reader low-frequency card seeking characteristic information; determining by a radio-frequency SIM card A whether an intensity of a low-frequency magnetic induction signal reaches a preset threshold value; if yes, receiving low-frequency card seeking characteristic information and transmitting card seeking response information through a radio-frequency channel; receiving by the card reader the card seeking response information, establishing a radio-frequency connection with the radio-frequency SIM card A, and opening a preset time window; when the preset time window closes, interrupting by the card reader a transaction process with the radio-frequency SIM card A and re-transmitting the low-frequency card seeking characteristic information; if receiving by the card reader card seeking response information transmitted by another radio-frequency SIM card B, ascertaining that a radio-frequency SIM card collision exists.