The invention provides a solar evacuated collector tube which comprises an inner-layer glass tube and an outer-layer glass tube. A vacuum layer is arranged between the inner-layer glass tube and the outer-layer glass tube. A glass cavity is formed in the bottom of the inner-layer glass tube and communicated with the vacuum layer through a hole, an annular sealing board for connecting the inner-layer glass tube with the outer-layer glass tube is arranged in the vacuum layer, and the vacuum space below the port, in the vacuum layer, of the hole and the space above the vacuum space are isolated. The upper surface of the annular sealing board is not lower than the lower side of the port. The glass cavity contains mercury. When the temperature of the mercury is lower than 90% of the boiling point of liquid in the inner-layer glass tube at the standard atmospheric pressure, the volume of the mercury is smaller than the volume of the glass cavity; when the temperature of the mercury reaches the boiling point, mercury expands so that the glass cavity and the vacuum space above the annular sealing space are filled with the mercury. The solar evacuated collector tube has the excellent anti-explosion performance, and an explosion is not likely to happen even under the environment that a pressure relief hole is not available.