We report both 23Na and 75As nuclear magnetic resonance (NMR ) studies on hole-doped Ca1-xNaxFe2As2 superconducting single crystals (x ≈ 0.67) with the superconducting temperature Tt =32 K.Singlet superconductivity is suggested by a sharp drop of the Knight shift 75K below Tc.The spin-lattice relaxation rate 1/T1 does not show the Slichter-Hebel coherence peak,which suggests an unconventional pairing.The penetration depth is estimated to be 0.24 μm at temperature T =2K.Here 1/75T1T shows an anisotropic behavior and a prominent low-temperature uptu,with 75T1 denoting the 75As spin-lattice relaxation time and T the temperature,which indicates strong low-energy antiferromagnetic spin fluctuations and supports a magnetic origin of superconductivity.