A spin thermoelectric effect in diluted magnetic semiconductor nanodevice is investigated. This nanodevice is modeled as a semiconducting quantum dot is connected to two diluted magnetic semiconductor leads. The spin transport of electrons through such nanodevice is conducted under the effect of an ac-field with frequency in the mid-infrared range and magnetic field. The thermoelectric parameters are expressed in terms of the photon-assisted tunneling probability, which has been derived by solving the Schrodinger equation of the present studied nanodevice. Results show that both Seebeck and Peltier coefficients together with figure of merit have high values. Also, the value of thermoelectric efficiency of this nanodevice is quit high. These results indicate that the present diluted magnetic semiconductor nanodevice is promising thermoelectric nanodevices for spin caloritronics applications that is for energy harvesting (Seebeck coefficient) and as coolers (Peltier coefficients) for nanoelectronics devices such as nanocontrollers and computer CPUs.