The present application relates to the technical field of wireless communication, and in particular to a reference signal transmission device, method and system, which are used to ensure normal communication between communication devices as much as possible when there is a frequency deviation between communication devices. A sending device provided by the present application includes: a processing module, configured to generate a reference signal, and the reference signal is a first-type reference signal; a sending module, configured to send out the reference signal generated by the processing module; wherein, in the time domain , in each subframe occupied by the first type of reference signal, the first type of reference signal occupies at least five symbols, and there are two symbols in at least five symbols, and the inter-symbol interval between the two existing symbols is not greater than two symbol. The above design of the first type of reference signal can ensure that when the frequency deviation between the devices communicating with each other is large, the receiving device estimates the frequency deviation through the reference signal of the above design and makes corresponding corrections, thereby ensuring that the frequency deviation between the devices is relatively large. normal communication.