Two-phase Ca2+-doped LaVO4:Eu3+ nanocrystals were prepared through a hydrothermal method with the help of SOD CITR and EDTA surfactants. The phase and morphology of the products were characterized by XRD and TEM, and the fluorescence performances were also recorded. The results indicated that Ca2+ ions were doped into the LaVO4:Eu3+ host lattice, impeding the aggregation of the nanocrystals and enhancing the luminescence intensity. The morphology transformation process and luminescence enhancement were systematacially investigated. The fluorescence intensity of the two selected samples could be completely quenched by Fe3+ ions without the disturbance of other ions, with the mechanism being due to the adsorption of Fe3+ ions onto the grains and a subsequent energy transfer from Eu3+ to Fe3+. Therefore, the present two Ca2+-doped LaVO4:Eu3+ samples can be applied as appropriate candidates for detecting Fe3+ ions with agility and sensitivity in aqueous solution.