Dispersion accumulation is a problem experienced in space division multiplexing communication systems that use multi-core fibers. To solve this problem， use of a 19-core photonic crystal fiber （PCF） with low loss dispersion compensation in the C+L band is proposed as multi-core PCFs have flexible and tunable dispersion. The optical properties of the fiber， such as dispersion， inter-core crosstalk （XT）， confinement loss， and bending loss are numerically simulated by the finite element method in combination with coupling mode theory. The results show that the multi-core fiber can significantly suppress XT and confinement loss， while achieving large negative dispersion in the C+L band. The fiber achieves a large negative dispersion of -9 572 ps/nm/km to -13 633 ps/nm/km and a low confinement loss of 2.04×10^-5 dB/km to 8.1×10^-3 dB/km in the C+L band. At the same time， the XT in the C+L band is between -88.96 dB/100 km and -33.33 dB/100 km， and the bend loss value meets the ITU-T recommendations of G.654 for 19-core PCFs with standard fiber sizes. Therefore， this fiber can play an effective role in dispersion compensation in multi-core fiber communication systems based on space division multiplexing technology.