We present quasi-simultaneous radio and X-ray observations of the black hole X-ray binary GRS 1739-278 of its 2015-2016 mini-outbursts, i.e. between 2015 June 10 and 2016 October 31, with the X-ray-to-radio time interval being less than one day. The monitor campaign was run by Swift in the X-rays and by JVLA in the radio (at both 5 GHz and 8 GHz). We find that the brightest radio emission is actually achieved during the soft sate, and the spectrum is marginally optically-thick with the spectral index α ≈ −0.28 ± 0.17 (flux F ν ∝ ν α ). For the radio emission in the hard state, we find a large diversity in the spectral index, i.e. a majority of radio spectra are optically-thick with −0.5 α 0.5, while a few are optically-thin, with α being lower than −1 in certain cases. We then investigate the correlation between the luminosities in radio (monochromatic at 5 GHz, L R ) and 1-10 keV X-rays (L X ) during the hard state. We find that for more than two orders of magnitude variation in the X-ray luminosity, this source exhibits a flat correlation with p ≈ 0.16 (in the form of L R ∝ L p X ), i.e. it belongs to the "outlier" (to the standard correlation with p ≈ 0.6) category that may follow a hybrid correlation. Both the slope and the corresponding luminosity range agree well with those in H1743-322, the prototype of the hybrid correlation. Theoretical implications of our results are discussed.