We present a wireless multimodal neural interface device to record neural activities of neurons in dorsal root ganglia (DRG) and muscle electrical activities (EMG) of the selected muscles of 4 limbs, while selectively manipulating neural activities in DRGs of freely locomoting cats via optogenetic stimulation. The neural interface device uses Bluetooth Low Energy radio to receive user-defined stimulation parameters and send the recording data. The neural interface has a plug-in structure formed by two vertical functional boards and one horizontal substrate board, resulting in dimensions of 3 × 3 × 3.3 cm3 and a weight of 6.5 g.