A series of RE2MoO6: 2%Er3+, 15%Yb3+ (RE=Y, Pr, Nd, Sm, Eu, Gd, Dy, and Lu) nanoparticles were prepared by citric acid-assisted sol-gel method. The upconversion luminescence (UCL) properties of block-shaped Gd2MoO6: 2%Er3+, 15%Yb3+ were the best among the materials obtained. In addition, the UCL properties of the investigated systems by two strategies could be further improved. Modulation of the crystal structure could be achieved by the substitution of rare earth ions in matrix lattice. The UC emission intensity of Gd2MoO6 doped with Y3+ (40%) was enhanced about 2.27 (2.52) more times than that of Y3+-absent samples excited at 980nm (1550nm). Secondly, dual wavelength was used as the excitation wavelength simultaneously: The green UCL intensity of RE2MoO6: 2%Er3+, 15%Yb3+ was almost not changed, while the red UCL intensity was enhanced compared to the sum of the red UCL intensities excited by 980nm and 1550nm, respectively. The UCL mechanism excited by dual wavelength was investigated in detail, in which the two co-operative excitation processes were presented.