The color-tunable up-conversion (UC) emission and infrared photoluminescence and dielectric relaxation of Er3+/Yb3+ co-doped Bi2Ti2O7 pyrochlore thin films prepared by a chemical solution deposition method have been investigated. The pyrochlore phase structure of Bi2Ti2O7 can be stabilized by Er3+/Yb3+ co-doping. Intense color-tunable UC emission and infrared photoluminescence can be detected on the thin films excited by a 980 nm diode laser. Two UC emission bands centered at 548 and 660 nm in the spectra can be assigned to 2H11/2, 4S3/2 → 4I15/2 and 4F9/2 → 4I15/2 transitions of Er3+ ions, respectively. A Stokes infrared emission centered at 1530 nm is due to 4I13/2 → 4I15/2 transition of Er3+ ions. The dependence of UC emission intensity on pumping power indicates that the UC emission of the thin films is a two-photon process. The thin films also exhibit a relatively high dielectric constant and a low dissipation factor as well as a good bias voltage stability. Temperature- and frequency-dependent dielectric relaxation has been confirmed. This study suggests that Er3+/Yb3+ co-doped Bi2Ti2O7 thin films can be applied to new multifunctional photoluminescence dielectric thin-film devices.