Dark matter is the dominant matter in the Universe. In this talk, I will introduce two major scenarios of dark matter: Axion dark matter and WIMP (Weakly Interactive Massive Particle) and show how radio telescopes can search and put constraints on their parameters. The first one is Axion, which is a compelling dark matter candidate of increasing scientific interests in recent years, and was originally postulated to solve the strong CP problem in particle physics. Axions can be converted into monochromatic radiation in the neutron star’s magnetosphere, constituting a unique window to probe its existence with a radio telescope. We used MeerKAT telescope for 10 hours to observe the isolated neutron star RX J0806.4-4123 in the UHF band. I will present the results of the constraints on Axion DM decay rate from the newly observed MeerKAT data. I will show that the (new) upper limit of the axion decay constant is in the mass range of 2.5-5 mu-eV (micro-Electronvolt), which corresponds to MeerKAT 544-1,088 MHz. The constraints from MeerKAT complements the laboratory-based axion dark matter searches and fills the gap between 810-1,090 MHz gap between ADMX and RBF experiments. In addition, we used China FAST telescope to observe the synchrotron emission of WIMP dark matter decay in COMA Berenices dwarf galaxy and obtained strong constraints on WMIP decay channels. I will analyze these two current results and give future prospects on using radio telescope to constrain dark matter.