The invention belongs to the technical field of building energy conservation and provides a solid magnesite foam concrete wallboard and a production technology of a building block, wherein the solid magnesite foam concrete wallboard is light in weight, high in strength and excellent in heat-insulating and sound-insulating effects. The solid magnesite foam concrete wallboard consists of 15-60% of magnesium oxide, 5-15% of magnesium chloride, 15-25% of water, 15-45% of inorganic padding, 0.5-1.5% of gas-generating agent, 0.01-0.1% of foaming agent, 0-1% of short fiber and a reinforcing material. The production technology provided by the invention has the advantages that: 1) the weight of the magnesite foam concrete can be controlled according to applications; 2) the shape of the magnesite foam concrete can be changed according to the applications; 3) more than 95% of micro-pore magnesite foam concrete has a bubble diameter between 0.1mm and 1mm, the bubble sealing property is excellent, bubbles are not communicated with one another, halogen reduction is avoided, the water resistance is excellent, the weight is light, the strength is high, the shock resistance is strong, and the heat-insulating and sound-insulating effects are excellent; 4) the padding can be selected according to a local condition by taking wastes and residues of a local factory, deposited materials in a river and a lake and the like as raw materials; and 5) production is convenient, energy is saved, environment is protected, and a wall building-block, a door core plate, a fireproof plate, a partition plate, a heat-insulating plate and a sound-insulating and sound-absorbing material can be manufactured.