The fluidized bed mixer or zero-gravity mixer features a dual-shaft design with paddles for powder mixing, ensuring a homogeneous mixture regardless of particle size, shape, or density, with a batch time of 1 to 3 minutes. It includes a bottom-opening system for quick and efficient discharge. With its stainless steel mixing body, it offers high mixing efficiency and is used in various sectors such as pharmaceutical, nutritional, food, chemical, biological, feed, and ceramics. Optionally, it can include a liquid spraying system and an air return device to balance pressures during the process. It offers multiple shaft configurations for each product and volume capacities ranging from 250L to 2,500L per batch.