As a new type of laser driver for suppressing laser plasma instability, the low-coherence laser driver holds significant research value in the field of laser inertial confinement fusion. To achieve large-bandwidth and high-power low-coherence pulse parametric amplification, this study provides a detailed analysis of the parametric matching characteristics of DKDP crystals with varying deuteration rates under Type-I collinear phase matching conditions. The fundamental parameters, including phase-matching angles, walk-off angles, and parametric bandwidths, are determined. The theoretical parameter bandwidth of the 58% deuterium-doped DKDP crystal is 180 nm. On this basis, a design for broadband low-temporal-coherence optical parametric amplification based on 58% DKDP crystals is proposed, and the theoretical model and the corresponding numerical model are established by the three-wave coupled equations. Furthermore, an experimental investigation of parametric amplification based on 58%-deuterium-doped DKDP crystals is conducted. The center wavelength of the broadband low-coherence signal light is set at 1053 nm, while the pump wavelength is fixed at 532 nm. The spectral width is 40 nm with a gain factor of 2.1. The results show that 58% DKDP crystal has a large gain bandwidth, and combined with the colinear phase-matching method, such crystals are expected to enable large-bandwidth and high-gain amplification of low-coherence light.