Bleached needle leaved wood napped pulp board and preparation process thereof

The invention relates to a bleached needle leaved wood napped pulp board and a preparation process thereof. The preparation process comprises the steps of disintegrating the bleached needle leaved wood pulp board with a hydra-brusher to form sizing agent, adding softening napping agent into the sizing agent, mixing uniformly, adding chelating agent and bleaching bactericide into the sizing agent,sending the sizing agent into a press master after finishing the reaction, pressing the sizing agent, filtering the water solution, washing with water, and then adding water to gain the sizing agent,adding napped pulp depredating agent into the washed sizing agent, mixing uniformly, pouring the decontaminated sizing agent into pulp pool, adding dispersant into the decontaminated sizing agent, making into napped pulp board with a pulp machine after mixing uniformly. When the fix quantity of the napped pulp board is 670 g/m to 720 g/m , the pop strength of the napped pulp board is less than 0.85kpa.m /g, the white content of the napped pulp board is more than 85%, the shaggy degree of the dry scattered napped pulp fiber is more than 19.0cm /g, the time for absorbing water is shorter than 8s, the moisture pickup is more than 8.9g/g, which meet the quality demand of GB/T21331-2008.