The invention provides a PIS data transmission method and device. The PIS data transmission method comprises the steps that network side equipment determines that a target cell is a unicast cell or amulticast cell; if the target cell is a unicast cell, the network side equipment sends the PIS data to the terminal side equipment in the target cell in a unicast mode; and if the target cell is the multicast cell, the network side equipment sends the PIS data to the terminal side equipment in the target cell in a multicast mode. According to the PIS data transmission method and device provided bythe invention, the PIS data can be determined to be sent to the terminal side equipment in a multicast mode or a unicast mode according to the number of the terminal side equipment in the target cell, so that the transmission quality of the PIS data is improved.