The magnetic properties and ground state of a new triangular-lattice antiferromagnetic candidate NdMgAl11O19 were studied by magnetization measurements and neutron scattering tehnique. The results of magnetization show strong easy-axis anisotropy perpendicular to Nd3+ triangular layer. Besides, the results of polarizarion neutron diffraction show that there is no magnetic ordering but a clear antiferromagnetic-like diffused scattering at 80 mK. It is likely that NdMgAl11O19 may possess a quantum-spin-liquid ground state. However, the details of the crystal field excitations on this material is still unclear. We propose to carry out inelastic neutron scattering measurements of CEF excitations on this new triangular-lattice antiferromagnet at high count-rate chopper spectrometer Merlin. We have prepared at least 5 g of powder for this measurement. We request 1 day of measurement time.