This work mainly presents the system development and clock transition spectroscopy detection of a transportable ⁸⁷Sr optical lattice clock. The optical clock system uses a miniaturized physical system with a size of 120 cm×50 cm×60 cm, which connects the modularized sub-optical system through fibers. After subsequent to cooling with a first stage 461 nm laser and a second stage 689 nm laser, a cold atomic cloud with an atomic number of 1.02×10 ⁶ and an atomic temperature of 5.45 μK is obtained. The lattice light with a magic-wavelength is used to load ⁸⁷Sr in one-dimensional optical lattice with a lifetime of 434 ms, and an atomic temperature in lattice of 4.63 μK. The atoms are detected using an ultra-narrow linewidth 698 nm clock laser to obtain the clock transition spectrum with distinguishable sidebands, the degenerate spectrum with narrow linewidth, the spin-polarized spectrum, and the Rabi-flopping curve. The spin-polarized spectrum with linewidth of 11.79 Hz is obtained under the condition of clock laser interrogating, which is fairly close to the theoretical value of Fourier limit linewidth and can be as the frequency reference for the future optical clock closed-loop.