The present document discloses control signaling transmission and demodulation method, system and terminal. The control signaling transmission method includes: a base station transmitting control signaling using different transmission technologies on available transmission resources in the second control signaling transmission area in the same RB. With present document, by configuring a pilot frequency port and dividing the transmission resources in the second control signaling transmission area in the RB, the control signaling of a plurality of UEs using different transmission technologies can be transmitted on the available transmission resources in the same RB, thus fully utilizing the transmission resources in the RB, improving resource utilization rate, enhancing control signaling capacity, and supporting the control signaling of more users.