Based on magnetohydrodynamic turbulence simulations, we generate synthetic synchrotron observations to explore the scaling slope of the underlying MHD turbulence. We propose the new 𝑄-𝑈 cross intensity 𝑋 and cross-correlation intensity 𝑌 to measure the spectral properties of magnetic turbulence, together with statistics of the traditional synchrotron 𝐼 and polarization 𝑃𝐼 intensities. By exploring the statistical behaviour of these diagnostics, we find that the new statistics 𝑋 and 𝑌 can extend the inertial range of turbulence to improve measurement reliability. When focusing on different Alfvénic and sonic turbulence regimes, our results show that the diagnostics proposed in this paper not only reveal the spectral properties of the magnetic turbulence but also gain insight into the individual plasma modes of compressible MHD turbulence. The synergy of multiple statistical methods can extract more reliable turbulence information from the huge amount of observation data from the Low- Frequency Array for Radio astronomy and the Square Kilometer Array.