In order to explore the interplay among heat, charge, and spin, we investigate the spin-related thermoelectricity of a hybrid double quantum dot Aharonov–Bohm interferometer with Rashba spin–orbit coupling (RSOC). Interestingly, the nonzero RSOC phase difference can induce significant spin-dependent thermoelectric transport. Not only can the strong violation of the Wiedemann-Franz law be obtained, but also a pure spin-Seebeck effect can be produced, which may serve as a pure spin-current generator. The influence of system parameters on thermoelectric coefficients (especially for spin counterparts) are analyzed in detail, and the underlying physics is further elucidated. Furthermore, the spin figure of merit can be much larger than the charge one, which, thus, provides a realistic possibility of engineering spin thermoelectric devices with high performance. These results obtained may be of interest for developing spin thermoelectric devices in the field of spin caloritronics.