The network data traffic has exhibited an explosive growth trend in the last few years. As the foundation of the global broadband network, optical fiber communication systems have carried more than 90% of the data traffic and developed towards multi-dimension, ultra-large capacity, and ultra-long distance. In this paper, we build an ultra-high capacity-distance product single-mode fiber transmission experimental system to simulate transoceanic transmission. In the transmitter, according to the optical signal-to-noise-ratio of the transmission link, different information entropies are used to generate polarization multiplexing probability shaping 16-order quadrature amplitude modulation signals with different transmission rates. The fiber transmission link is composed of the ultra-low loss large-effective-area fiber and the ultra-wideband low-noise C-band erbium-doped optical fiber amplifier. The experimental system uses 129 wavelength channels (the wavelength range is 1529.8 nm to 1568.2 nm) and realizes the transmission capacity of 28.09 Tbit/s and the transmission distance of 12000 km. Therefore, a capacity-distance product of 337 Pbit·s^-1·km is achieved.