The invention discloses a sub-critical miniature reactor driven by neutron tubes. The sub-critical miniature reactor comprises fuel rods, the neutron tubes, a coolant, cladding tubes, a reflecting layer, a shielding layer and other ingredients, wherein the neutron tubes are taken as neutron sources for operation of a sub-critical miniature reactor and are uniformly dispersed and distributed in a sub-critical reactor core, and the neutron-flux density distribution of the reactor core is initiatively flattened in design. The quantity of neutrons output by each neutron tube in the reactor core in unit time can be continuously adjusted, so that power in each position in the reactor can be continuously adjusted, and the output power in each position of the reactor core is actively controlled. Under the accident condition, a power supply for the neutron tubes can be turned off at any time as required, reactor shutdown is completed, and serious accidents are completely eradicated. Due to the advantages, the reactor has high safety and economic performance and has great significance in improvement of geometric dimension miniaturization and maneuverability of the reactor.