The invention discloses a lightweight concrete product and a production method thereof. The method comprises the following steps: (1) adopting a desulfurizer slurry wet process to absorb sulfur dioxide inside flue gas, so as to form a flue gas absorbed slurry, wherein a desulfurizer slurry is a slurry formed by magnesium oxide and industrial wastewater; (2) mixing the flue gas absorbed slurry, industrial solid waste, magnesium oxide, lightweight aggregate, sand aggregate and an additive to form a mixture, wherein the mass ratio of the flue gas absorbed slurry, industrial solid waste, magnesiumoxide, lightweight aggregate, sand aggregate to the additive is 55-85 to 20-40 to 8-35 to 8 -15 to 5 -15 to 0.1 -10; (3), forming and curing the mixture so as to obtain the lightweight concrete product. According to the production method disclosed by the invention, a flue gas desulfurization problem can be solved, an industrial wastewater treatment problem also can be solved, and simultaneously,a cyclic utilization problem of industrial solid waste can be solved.